Composition of an anti-scale-forming agent

ABSTRACT

A composition for an anti-scale-forming agent includes oil-based polyalkylenes, amines phosphorous and oxygen in a polymer for providing dispersivity and anti-oxidation and having the following formula:                    
     By integrating both characteristics into a single polymer, the anti-scale-forming agent in accordance with the present invention can be used as an anti-scale-forming agent for a manufacturing process in a petroleum refinery plant or the like chemistry factory. R 1 , R 2  and x are defined herein.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The invention relates to a composition of an anti-scale-forming agentfor dispersing scales and for anti-oxidation, and more particularly toan additive which can be added during a chemical process of aheat-exchanger, a reactor, a distillation tower or the like in a powerplant, a petroleum refinery or the like chemistry plant.

(2) Description of the Prior Art

An anti-scale-forming agent is one of typical chemicals that are widelyused in petroleum-related and petroleum-refinery industry. Generally, inan intern process of the industry including an oil-cracking process, areforming process or a de-ethylene process, the reaction temperature maybe as high as 200˜500° C. Meanwhile, hydrocarbons in a reaction chamberwill be deformed through oxidation or polymerization to generate scales.The scales accumulated in the piping and the furnace wall may affect theprocessing flow, more even block the valves and piping, and lower theheat-transfer efficiency. As a result, energy is wasted and productionwill be inevitably reduced due to frequently shutdown for cleaning thescales in the piping. Therefore, usage of anti-scale-forming agent in achemistry plant is important and frequently seen.

The forming of scales is one of general chemistry phenomena. The scaleis a gel-form or carbonic-acid coke product that is cracked from apolymer, in which the polymer is formed from a reaction mechanism offree radicals through oxidation upon impurities or the hydrocarbonitself. In addition, in the case that the impurities include metalsubstance such as Cu or Fe, the forming of free radicals will beaccelerated and thus the forming of scales will be serious. Therefore,the anti-scale-forming agent is usually made to be a good anti-oxidizeror a metal de-activator. Actually, there are already several kinds ofthe anti-scale-forming agents in the market to meet various applicationsin the industry; such as the U.S. Pat. No. 4,775,495 disclosing acontrol method upon oxidation for a petroleum-related process, and theU.S. Pat. No. 5,211,836 introducing anti-oxidants and aninterface-dispersing theory for various process to enhance economicefficiency.

SUMMARY OF THE INVENTION

Accordingly, it is a primary object of the present invention to providea composition for an anti-scale-forming agent that can disperse thescales and prevent from the oxidization. The scale-dispersivity of theagent is obtained through a dispersing theory for ahydrophilic/oil-philic balanced interface agent in a molecular formula.By integrating the dispersivity and the anti-oxidization in a singlepolymer, the excellent anti-scale-forming agent of the present inventioncan be formed and can be applied to the petroleum-refinery and otherchemistry processes for providing effects of anti-oxidizing andanti-scale-forming.

To achieve aforesaid purposes, the composition of the anti-scale-formingagent in accordance with the present invention includes polyalkylenes,amines phosphorous and oxygen in a polymer for providing substantialdispersivity and anti-oxidization. The chemical formula of the polymercan be expressed as:

(R¹R²)_(x)POR² _(3−x)

in which R¹ and R² are selected from polyalkylenes, poly etheramines orpolyamines having oxyakLenes. In the expression, O is oxygen, P isphosphorous, and x is 1 or 2.

In application, aforesaid formula (R¹R²)_(x)POR² _(3−x) can bechemically structured as follows.

R³=alkyl, e.g. polyisobutyleneyl (PIB)

In addition, the structure shown above can be obtained through thefollowing reaction.

x=1 or 2

(A) is made by the following formula:

(B)+polyisobutylenesuccinic anhydride (PIBSA) {right arrow over(_(Different Mole Ratio))}  (A)

Select one of polyalkylenes formed by alkylenes through a polymerizationreaction. The polyalkylene is then used to derive an acid-anhydride, andthe acid-anhydride is further used to form an additive product throughreaction with oxygen and phosphorous containing amine. The additiveproduct has a high oil-resolvability, and at least two amines forbonding effect, and phosphide for anti-oxidizing. The additive productas the anti-scale-forming agent according to the present invention canintegrate at least two characteristics into a single polymer so that itcan contribute greatly to the oil-refinery factories and other chemistryfactories.

All these objects are achieved by the composition of theanti-scale-forming agent described below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be specified with reference to itspreferred embodiment illustrated in the drawings, in which

FIG. 1 is a schematic view of a chemistry equation and a reaction for afirst embodiment of the anti-scale-forming agent in accordance with thepresent invention;

FIG. 2 is an ASTM D3241 testing plot by adding the anti-scale-formingagent of the present invention; and

FIG. 3 is a comparison of some ASTM D3241 testing results byrespectively adding the anti-scale-forming agent of the presentinvention and some commercial anti-scale-forming agents into the oil.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention disclosed herein is directed to a composition of ananti-scale-forming agent. In the following description, numerous detailsare set forth in order to provide a thorough understanding of thepresent invention. It will be appreciated by one skilled in the art thatvariations of these specific details are possible while still achievingthe results of the present invention. In other instance, well-knowncomponents are not described in detail in order not to unnecessarilyobscure the present invention.

According to the present invention, an anti-scale-forming agent withexcellent anti-oxidization and anti-scale-formation is provided tointegrate oil-based polyalkylenes, amines phosphorous oxygen amines in apolymer. The anti-oxidization provided by the polyalkylenes withphosphors and the bonding capability provided by the amines with aminosenable the polymer of the present invention to have thescale-dispersivity and the anti-oxidization at the same time.

In the present invention, the polyalkylenes can be derived fromoil-based polyalkylenes through polymerization upon alkylenes. Thepolyalkylene can have a molecular weight of above 600, preferably rangedbetween 600 and 1500. In the present invention, the amine can be one ofpolyetheramines or poly oxyalkylene amines which includes at least anorganic function. Suitable polyamines for the present invention can beselected from the following chemicals.

a. N₂HCH₂CH₂NH₂ (ethylene diamine, EDA)’,

b. H₂N(CH₂)5NH2 (1,6-diamino hexane)’,

c. H₂N(CH₂)₂NH(CH₂)₂NH₂ (diethylenetriamine, DETA)’,

d. H₂NC(CH₃)HCH₂ (OCH₂C(CH₃)H)_(x)NH₂ (x=2˜3, D-230)’,

e. H₂N(CH₂)₂NH(CH₂)₂NH(CH₂)₂NH₂ (triethyleneteramine, TETA)’,

f. (CH₃CH₂)₂N(CH₂)₃NH₃(N, N-diethyl-1,3-propane diamine)’,

g. H₂N(HC(CH₃)H₂CO)_(x)H₂C₂-(CH₂—(OCH₂C(CH₃)H)X—NH₂)₂C₂H_(5’,)

h. H₂N(CH₂CH₂O)₂CH₂CH₂NH₂,

i. (CH₃)₂N(CH₂)₃NH₂ (N, N-dimethyl-1, 3-propane diamine)

The amine above might have a molecular weight of above 200, preferablyranged between 200and 2000.

In the present invention, the anti-scale-forming agent can have apreferred chemistry structure as follows.

R³=PIB

R⁵=H, CH₃ or C₂H₅

x=1 or 2

y=1˜20

In the above formula, poly oxyalkylene amines, PIB and the phosphidesare coexistent.

One suitable forming method for producing the anti-scale-forming agentof the present invention can include a step of forming a coupler bycoupling POCl₃ and polyetheramine by ridding off HCl. On the other hand,isobutylene can be used to derive a PIB with a molecular weight of 800to 2000, through a polymerization. The PIB is then used to form a PIB-SAwith a molecular weight of 300 to 2000. Finally, the coupler and thePIB-SA are reacted to derive the final product, the anti-scale-formingagent of the present invention as shown in FIG. 1.

The novel anti-scale-forming agent of the present invention can beapplied to any heat exchanger, reactor, or distillation tower in a powerplant or a chemistry factory. Moreover, the ASTM D3241 testing can beused to verify the agent. According to the present invention, it isforeseeable that various anti-scale-forming agents of the same kind canbe derived to meet specific factory processes.

Effects and various advantages by applying the present invention will befurther described through the preferred embodiment and the relatedtesting procedures raised below.

EMBODIMENT

Use double amount of TBF respectively to dissolve POCl₃ (5.4 g, 0.035mole) and polyetherdiamine (24.15 g, 0.105 mole). Under the roomtemperature, titrate the POCl₃ into the polyetherdiamine and willdissipate above 10° C. heat. Heat the solution to 60° C. and keep 4hours for reaction. Then, lower the solution to the room temperature andrid off the THF by lowering the pressure and increasing theconcentration. Dissolve one concentrated sample by CHCl₃, neutrallyreact the sample solution with an NaHCO₃ solution to derive a middleproduct HCl, and then extract a layer of organics. After apressure-lowering and concentration process to rid off CHCl₃, a middleproduct named B1 is obtained. Bring PIB-SA (11.02 g, 0.00992 mole) intoa tri-neck bottle, and add in B1 (4.8532 g, 0.00612 mole) and overdoseToluene as the solvent. Have the PIB-SA solution heated and stirred to100° C. and kept 4 hours for reaction. Then, after a pressure loweringand concentration process, the Toluene is removed and a final productcan be obtained for a further FT-IR testing. Under a reactiontemperature of 60° C. for the FT-IR testing, a specimen of the finalproduct is verified to have O═P—N—H fue to the existence of threeabsorption peaks at 1020.4 cm⁻¹, 907.1 cm⁻¹ and 1592.2 cm⁻¹. In a secondprocedure of 100° C. reaction temperature, the specimen of the finalproduct is verified to have amic acids due to the existence of twoabsorption peaks at 1641.9 cm⁻¹ and 1545.3 cm⁻¹ (weak). The completionof the reaction can be ascertained by observing the disappearance of twoIR absorption peaks for the specimen at 1786.0 cm⁻¹ (strong) and 1862.2cm⁻¹ (weak).

In the following testing processes, analytic characteristics of theanti-oxidization agent in the preferred embodiment of the presentinvention will be revealed. In the following description, ΔT for addingthe anti-oxidization agent is according to the ASTM D3241 testing specs.

Table 1 shows various compositions of anti-scale-forming agents, formedunder 80° C. The anti-oxidization effect of the agents in 3 hoursaccording to the ASTM D3241 and the titration value for the first, thesecond and the third degrees, amines are also shown. In the table, bothPOCl₃ and DCP have the phosphor. Polyetherdiamine (D-230 shown inFIG. 1) and phenylene diamine have the amino. It is found, by comparingA1 with A3 or by comparing A4 with A4, that the composition having theD-230 can reveal the characteristics of the first and the second degreeamines, and thus can present better bonding effect. It is also found, bycomparing A1 with A3, that ΔT for the agent with the D-230 is higherthan that for those with the phenylene diamine. Therefore, the A1 withthe D-230 can present better anti-oxidization capability.

FIG. 2 is an ASTM D3241 testing plot by adding the anti-scale-formingagent of the present invention. The testing pressure and temperature are500 psi and 371° C., respectively. The 150-ppm anti-oxidization agent isadded by a flow rate of 1.5 cc/min. From FIG. 2, it is found that,during a petroleum refinery process, ΔT of the testing will increase asthe reaction time. After adding the anti-oxidization agent B1, ΔT of thetesting at a same reaction duration is substantially reduced. Therefore,disadvantages of scale-forming and over oxidization caused by increasingthe reaction time can be avoided.

FIG. 3 is a comparison of some ASTM D3241 testing results byrespectively adding the anti-scale-forming agent of the presentinvention and some commercial anti-scale-forming agents into the oil.The testing pressure and temperature are 500 psi and 371° C.,respectively. The 150-ppm anti-oxidization agent is added by a flow rateof 1.5 cc/min. From FIG. 3, it is found that the anti-scale-formingagent A3 of the present invention can reduce the ΔT of the oil having noanti-scale-forming agent added. However, the anti-scale-forming agent A3of the present invention has obviously not achieved a commercial scale.On the other hand, the anti-scale-forming agent A1 of the presentinvention does have achieved the commercial scale or a better scale.

The anti-oxidization agent of the present invention, dependent upon theprocesses and the equipment for use, can be variously and optimallycomposed to have improved temperature-controllability and theanti-oxidization for being applied to a heat exchanger, a reactor, adistillation tower or the like in a power plant, a refinery factory orthe like chemistry factory.

While the present invention has been particularly shown and describedwith reference to a preferred embodiment, it will be understood by thoseskilled in the art that various changes in form and detail may bewithout departing from the spirit and scope of the present invention.

TABLE 1 THEORETICAL WEIGHT MOLE AMINO TOTAL SPECIMEN REACTOR RATIO RATIOCONDITION TITRATION VALUE AMINE A1 PIB-SA/B1 11.02:4.92  1.5:1.0 80° C.1.34 0.56  {POCl₃/D-230 3 hr (1:3)} A2 PIB-SA/B2 4.24:3.36 1.5:1.0 80°C. 1.07 0.114 {DCP/D-230 3 hr (1:4)} A3 PIB-SA/B3 3.09:0.69 1.5:1.0 80°C. — — {POCl₃/Pheny- 3 hr lene diamine (1:3)} A4 PIB-SA/B4 0.72:0.501.5:1.0 80° C. — — {DCP/Pheny- 3 hr lene diamine (1:4)} 1^(ST) 2^(ND)3^(RD) DEGREE DEGREE DEGREE ASTM SPECIMEN AMINE AMINE AMINE COLORTESTING NOTES A1 0.51  0.05 0 Transparent  1° C. low 1R Orange A2 0.1140.05 0 Transparent 1R Orange A3 — — — Dark Green 22° C. low 1R A4 — — —Dark Green 1R Sticky

What is claimed is:
 1. An anti-scale forming composition containing ananti-scale-forming agent having a formula:

wherein R¹ is a polyalkylene group, and R² is a polyether or apolyoxyalkylene, and x is 1 or
 2. 2. The composition according to claim1, wherein R¹ is polyisobutylene and R² is polyoxypropylene.
 3. Thecomposition according to claim 1, wherein the composition hasdispersivity and an anti-oxidization properties in accordance with ASTMD3241 testing.
 4. The composition according to claim 1, wherein thepolyalkylene has a molecular weight of from 600 to
 1500. 5. Thecomposition according to claim 1, having a formula

in which R³ is polyisobutylene, R⁵ is hydrogen, methyl or ethyl, and yis an integer ranging from 1 to
 20. 6. A composition according to claim1, wherein the amine portion of the polyether or polyoxyalkylene of theformula is derived from: H₂NCH(CH₃)CH₂(OCH₂C(CH₃)H)_(x)NH₂ (x=2˜3), orH₂N(CH₂CH₂O)₂CH₂CH₂NH₂.
 7. An anti-scale forming composition containingan anti-scale-forming agent having a formula:

wherein R¹ is a polyalkylene group, the amine portion, —NH—R²—NH—, ofsaid formula is derived from: H₂NCH₂CH₂NH₂ (ethylene diarnine, EDA),H₂N(CH₂)₅NH₂ (1,6-diamine hexane), H₂N(CH₂)₂NH(CH₂)₂NH₂ (diethylenetriamine, DETA), H₂N(CH₂)₂NH(CH₂)₂NH(CH₂)₂NH₂ (triethylenetetramine,TETA), (CH₃CH₂)₂N(CH₂)₃NH₂ (N, N-diethyl-1,3-propane diamine), or(CH₃)₂N(CH₂)₃NH₂ (N, N-dimelthyl-1,3-propane diamine); and x is 1 or 2.